RU2759966C1 - Method for purification of the drainage water of a rice irrigation system - Google Patents

Abstract

FIELD: treatment of water.SUBSTANCE: invention relates to purification of drainage water and can be used in water-protective measures when obtaining additional volumes of clean water for irrigation land reclamation. The method for purifying the drainage water of a rice irrigation system includes passing the drainage water through a filtering cassette with a sorbent, installed in the channel of the discharge canal of the irrigation system. A phytosection is used as a filtering cassette, constituting a section of the discharge canal, planted once at the ends whereof to the entire width and to a distance along the length of the discharge canal, depending on the chemical composition of the drainage water after passage thereof through the phytosection, preliminarily in the first year of the drainage water purification on the rice irrigation system in autumn in the period of water supply termination to the rice system, is perennial Tatora halophyte (lat. Schenoeplectus tatora). In the spring of the first and the subsequent years of drainage water purification on the rice irrigation system, Eichornia halophyte (lat. Eichhornia crassipes), or a "water hyacinth", is planted on the surface of the drainage water in the discharge canal. The phytosection is formed by the schemesa-b-a, whereinais the distance along the length of the sectional discharge, in metres, with the planting of Tatora halophyte, andbis the distance along the length of the sectional discharge, in metres, with the planting of Eichornia halophyte, whereinaequals 10, 20 or 30 m, andbequals 50, 100 or 150 m.EFFECT: invention provides an increase in the efficiency of purification of drainage water from organic substances, biogenic elements.1 cl, 1 dwg, 5 tbl, 1 ex

Description

The inventions relate to the treatment of drainage effluents and can be used in water protection measures when obtaining additional volumes of clean water for irrigation reclamation.

A known method for purifying wastewater from pesticides (US Pat. RU No. 2060961, C02F 1/58, 27.05.1996). According to this method, wastewater treatment from pesticides is carried out by introducing active carbon into the water and settling.

The disadvantage of this method is the unevenness of the introduction of activated carbon into the water, and, consequently, the wastewater treatment. Low spraying efficiency with ground spray units and with the help of aircraft.

There is a known structure for the treatment of collector-drainage and wastewater (US Pat. RU 2062634, B01D 36/04), being built on the route of an open collector-drainage channel, consisting of sequentially installed sedimentation tanks and sorption filters made in the form of wells equipped with removable mesh containers, filled with sorbent. The disadvantage of this structure is the high cost of the sorbent used: modified mudstone.

There is a known method of purification of drainage flow and a device for its implementation (US Pat. RU No. 2091538, E02B 11/00, 09/27/1997). According to this method, drainage drainage is purified by means of mechanical retention of impurities, followed by the removal of pesticide residues by passing the drain through a fibrous material.

The disadvantages of this method are large labor costs for granulating sapropel, processing the fibrous filter material with alumina, manufacturing the filter cartridge and extracting the fibrous filter material from it.

There is a known method for cleaning the drainage drain and a device for its implementation (US Pat. RU No. 2401804, C02F 1/28, B01D 25/02, B01D 39/06, E02B 11/00, C02F 103/10, 20.10.2010). According to this method, removal of mechanical impurities, organic substances, heavy metal ions, as well as excess salts in the drainage-discharge channel by passing the drainage flow through a filter matrix fixed in the channel of the drainage-discharge channel, containing sorbents in the following sequence, taking into account the occupied volume of sorbents in filter matrix: shell rock - 50%, glauconite sand - 30%, expanded clay - 20%. The filtering matrix is made in the form of a rigid metal frame made of a steel corner, the bottom and side edges of which are covered with sheet steel. On the working side, which ensures the passage of the drainage runoff, the frame is equipped with a trash grate. The frame contains three inserted removable cassettes with sorbents, located in a certain sequence along the path of the drainage flow: shell rock, glauconite sand, expanded clay. Each removable cassette is a metal case made of a steel corner, the bottom and side edges of which are covered with sheet steel. The cassette body is equipped on the working sides with brass nets, with fibrous filtering material attached to them from the inside, and has two ties around the perimeter in the form of sheet steel strips, acting as stiffeners, with mounting loops.

The disadvantages of this method are large labor costs for the manufacture of the matrix, its operation and processing.

A complex of facilities for the treatment of domestic wastewater is known (US Pat. RU No. 2181703, C02F 9/00, 04/27/2002). According to this method, the purification of domestic wastewater is carried out due to the successively installed downstream gratings, sand traps, settling tanks, aeration tanks and multi-section biological ponds with an underground biosorption filter. The surface of the biosorption filter is planted with Salixalba willows. The banks are planted with cattail, reeds, and the water hyocinth (eichornia) is planted in the pond itself. A floating aerator is installed in the first section of the biopond; filter dams are installed between the sections of the biopond, which in turn have a non-filtering base.

The disadvantages of this method are large labor costs for the manufacture of this complex, its operation and processing.

A known method for neutralizing wastewater and a device for its implementation (US Pat. RU No. 2359924, C02F 3/32, 27.06.2009). According to this method, wastewater disposal consists in supplying wastewater to oval-shaped working channels with eichornia and maintaining a constant water level in them and laminar movement of water at the same speed in the working channels. In this case, the installation itself is made of a distribution channel with a receiving grate located above it, and a collecting drainage channel, interconnected by a series of oval-shaped working channels with eichornia, located perpendicular to the distribution channel and the collecting drainage channel and / or at an angle to them, equipped with transverse movable partitions.

The disadvantages of this method are large labor costs for the reconstruction of the drainage and discharge network of the rice irrigation system, its operation under the required conditions, as well as the creation of a number of working channels located perpendicular to the distribution channel and the collecting drainage channel and / or at an angle to them in the conditions of the rice system.

The closest technical solution to the claimed proposal is a method for purifying drainage flow, including passing the drainage flow through a filter cartridge installed in a cartridge-holding device installed in the bed of the discharge channel of the irrigation system (RF patent No. 2505486, class C02F 1/28, U02V 13/00, A01G 25/00, 2014).

The disadvantage of the known method is the laboriousness of the construction of a monolithically fixed cassette-holding device in the channel of the discharge channel, which leads to a narrowing of the channel flow from 30 to 60 percent, depending on the cross-section of the discharge channel, which in turn leads to an increase in velocities in this place, and in total with the cassette-holding the device, which acts as a backwater, leads to a rise in the water level in the canal above the critical one, up to the spill of sewage on both sides of the canal and prevents the outflow of drainage and waste water from the checks. At the place where the cassette-holding device is installed, suspended particles fall out, which leads to local silting of the channel. The cassette-holding device, made of a rigid metal frame with a metal mesh fixed on it, filled with dried reed and reed plants, not only prevents the passage of fish in the channel, but also contributes to its jamming and death, which worsens the ecological situation in the rice irrigation system.

The technical result of the invention is to improve the efficiency of cleaning the drainage runoff from organic substances, biogenic elements, mechanical impurities by using halophytes for their purification; improving the reclamation state of soils and the ecological situation in rice fields by reducing suffusion and removal of nutrients from the soil; reduction of the cost of rice due to a decrease in the irrigation rate and a decrease in the rates of application of organic and mineral fertilizers.

The technical result is achieved by the fact that in the method of purifying the drainage runoff of the rice irrigation system, including passing the drainage runoff through a filtering cartridge with a sorbent installed in the bed of the discharge channel of the irrigation system, a phytosection is used as a filtering cartridge, which is a section of the discharge channel, at the ends of which in the entire its width and the distance along the length of the discharge channel, depending on the chemical composition of the drainage runoff after it passes the phytosection, in the first year of cleaning the drainage runoff on the rice irrigation system in the fall, when the water supply to the rice system is stopped, the perennial Tator halophyte (lat. Schenoeplectus tatora), in the spring in the first and subsequent years of purification of drainage runoff on the rice irrigation system, the halophyte Eichornia "water hyacinth" (lat. Eichhornia crassipes) is planted on the water surface of the drainage runoff in the discharge They flow according to schemes a - b - a , where a is the distance along the length of the district discharge, in meters with the landing of the Tator halophyte, a b is the distance along the length of the district discharge, in meters, with the landing of the Eichorniy halophyte, while a is 10, 20 or 30 m, a b - 50, 100 or 150 m.

The novelty of the claimed invention is due to wastewater treatment using phytosections consisting of Tator halophytes (Latin Schenoeplectus tatora) and Eichhornia "water hyacinth" (Latin Eichhornia crassipes), which are planted on a specific section of the group and / or local canal of the drainage-waste network of the rice irrigation system.

The use of two types of halophytes allows you to cover a wider range of organic substances and biogenic elements for better purification of drainage and waste runoff by improving filtration properties by settling suspended particles, which occurs due to a decrease in the speed of water in the canal when it passes through the stems and roots of halophytes; accumulation of organic substances by halophytes, as well as some metals: cadmium, copper, lead, zinc, which are in the drainage drain and are difficult to dissolve; absorption by halophytes of organic substances and nutrients from the drainage runoff: nitrogen, phosphorus, potassium, calcium, magnesium, manganese, sulfur; saturation of drainage flow with oxygen during photosynthesis of halophytes; detoxification of drainage flow by converting toxic substances into non-toxic ones due to their accumulation by halophytes; creation of conditions for the unimpeded passage of fish through the canals, as well as optimization of the speed regime of discharge flow in the canal.

The planting of the Eichornia halophyte between the Tator halophyte is due to the need to create favorable conditions for the intensification of its cleansing ability and biogenic activity, as well as to control the spread of Eichornia on the water surface of the drainage runoff.

Due to the fact that each of the alternating halophytes has its own spectrum of organic substances and biogenic elements, which they can accumulate and absorb over a certain period of time, then, based on the results of chemical analysis of drainage runoff samples, a decision is made on the length of planting of halophytes in group and / or local canals of the drainage and discharge network of the rice irrigation system.

Planting the Tator halophyte into the group and / or local canals of the drainage and discharge network makes it possible to control the filtration outflow of irrigation water from the rice pad by creating the required backwater in the drainage channel due to the passage of the drainage and discharge runoff through the halophyte, and, consequently, to reduce the loss of irrigation water, to promote reduction of suffusion and removal of nutrients from the arable horizon of rice paddies.

Planting the Tator halophyte over the entire width of the discharge channel allows achieving the effect of a filter cartridge and creating the filtration and velocity conditions in the discharge channel required to intensify the purification capacity and biogenic activity of the Eichornia halophyte.

The essence of the invention is illustrated by a drawing, where FIG. 1 shows a discharge canal with a phytosection located in it: a is the distance along the length of the discharge canal, in meters, with the landing of the Tator halophyte, b is the distance along the length of the discharge canal, in meters, with the landing of the Eichornia halophyte, l is the length of the phytosection, 1 is the discharge channel.

The method for cleaning the drainage runoff of the rice irrigation system is carried out as follows In the first year of the implementation of the method for cleaning the drainage runoff of the rice irrigation system, in various discharge channels, phytosections are formed according to the following schemes: a - b - a , where a is the distance along the length of the discharge channel, in meters , with the landing of the Tator halophyte, and b is the distance along the length of the discharge channel, in meters, with the landing of the Eichornia halophyte, and l is the length of the phytosection.

At the same time, the planting of the perennial Tator halophyte is carried out once in the fall in the first year of the implementation of the method for cleaning the drainage runoff of the rice irrigation system after the water supply to the rice irrigation system is turned off along the entire width of the discharge canal, including the slopes, and the Eichornia halophyte planting is performed annually in spring after water is supplied to the rice irrigation system. system directly on the water surface of the drainage and discharge flow in the discharge channel.

Every year in the fall, before the water supply to the rice irrigation system is turned off, Eichornia halophyte is collected from the water surface of the discharge canal and is applied to the rice paddies, and after the water supply to the rice irrigation system is cut off, Tator halophyte is mowed and, like Eichorniya, after grinding, it is applied to the rice paddies. to enrich the soil with organic substances and increase the reclamation state of the soil, after which planned annual non-vegetation repair and restoration and operational work on the rice irrigation system are carried out.

In order to establish the economic-ecological-optimal distance for the values of a and b in the phytosection, their various options for the length of planting along the length of the discharge channel are accepted, then immediately after the passage of the drainage-discharge runoff of the phytosection, samples were taken and their chemical composition was determined, after which it is compared with the results of the chemical composition of samples from the discharge channel without phytosections (control), and a conclusion is made about the most effective phytosection scheme.

An example of the implementation of the method for cleaning the drainage runoff of the rice irrigation system Testing of the method for treating the drainage runoff of the rice irrigation system was carried out in the Krasnodar Territory in the JSC "Chernoerkovskoye" of the Slavyansky District (2nd department). All fields of the farm use Krasnodar-type maps, and the cultivated rice crop was - variety Limanny. Irrigation regime - constant flooding. Fertilizer dose - N120P90K60.

In the first year of the implementation of the method, phytosections were formed in various local discharge according to the following schemes: a - b - a , where a is the distance along the length of the district discharge, in meters, with the landing of the Tator halophyte, and b is the distance along the length of the district discharge, in meters , with the planting of Eichornia halophyte, l is the length of the phytosection.

At the same time, the planting of the perennial Tator halophyte was carried out once in the fall in the first year of the implementation of the method for cleaning the drainage flow of the rice irrigation system after the water supply to the rice irrigation system was turned off along the entire width of the discharge canal, including the slopes, and the Eichornia halophyte was planted annually in spring after water was supplied to the rice irrigation system. system directly on the water surface of the drainage and discharge flow in the discharge channel.

In order to establish the economic-ecological-optimal distance for the values of a and b in the phytosection, three groups of schemes were adopted with the following options: Group 1: 10-50-10, 10-100-10, 10-150-10; 2nd group: 20-50-20, 20-100-20, 20-150-20; Group 3: 30-50-30, 30-100-30, 30-150-30.

To determine the efficiency of phytosections during the growing season of rice, at the beginning, middle and end of the growing season, samples of drainage and discharge runoff were taken and its chemical composition was determined (Tables 1-3). In this case, the sampling of the drainage-waste runoff was carried out immediately after it passed the phytosection.

To assess the efficiency of purification of drainage and waste runoff after it passed a phytosection, samples were also taken from a local canal without phytosections - control (Table 4).

It was found that the greatest contamination of the drainage and waste runoff was observed during the period of the end of tillering and before the phase of full milk - the beginning of the wax ripeness of rice, when a layer of water of 10-12 centimeters is created and maintained on the checks and the maximum filtration of irrigation water from the check into the rice drainage network occurs. irrigation system (table 2).

From tables 1-3 it was found that the most effective schemes of group 2, and the most effective variant of phytosection in the second group according to the scheme a - b - a - 20-150-20.

Every year in the fall, before the water supply to the rice irrigation system was turned off, Eichorniya's halophyte was collected from the water surface of the discharge canal and added to the rice paddies, and after the water supply to the rice irrigation system was turned off, Tator's halophyte was mowed and, like Eichorniya, after grinding, it was applied to the rice fields. checks to enrich the soil with organic substances and improve the soil reclamation state, after which planned, annual non-vegetation repair and restoration and operational work on the rice irrigation system were carried out.

It has been proven that the creation of a backwater in the local canal due to the passage of drainage-discharge flow through the phytosection reduces the filtration outflow of irrigation water from the rice pad, reduces the loss of irrigation water, reduces the suffusion and removal of nutrients from the arable horizon, which, along with the introduction of halophytes into rice paddies, leads to to improve the reclamation state of soils and the ecological situation in the rice irrigation system (table 5). To assess the change in the soil reclamation state, soil samples were taken from rice paddies of three rice fields with local canals belonging to the second group of phytosection schemes.

Analysis of the data in Table 5 showed an improvement in the reclamation state of the soils of rice fields and confirmed the effectiveness in comparison with the control of the proposed method for cleaning the drainage runoff of the rice irrigation system (Table 5).

By reducing the losses of irrigation water by reducing the filtration outflow of irrigation water, and, consequently, reducing the suffusion and removal of nutrients from the arable horizon from the rice pad, it was possible to reduce the irrigation rate by 10%, reduce the dose of organic and mineral fertilizers by 15%, and reduce the cost of rice production by 7%.

Claims (1)

A method for purifying drainage runoff from a rice irrigation system, including passing the drainage runoff through a filtering cartridge with a sorbent installed in the bed of the discharge channel of the irrigation system; the length of the discharge canal, depending on the chemical composition of the drainage runoff after it passes the phytosection, beforehand in the first year of cleaning the drainage runoff on the rice irrigation system in the fall, during the period when the water supply to the rice system is cut off, a perennial Tator halophyte (Latin Schenoeplectus tatora) is planted once. first and subsequent years cleaning drainage flow rice irrigation system to the water surface of the drainage flow in the discharge channel precipitated halophyte Eichhorn "water hyacinth" (lat Eichhornia crassipes.), thus forming fitosektsii carried out according to schemes a - b - a where a - rasstoyatsya not along the length of the district discharge, in meters, with the landing of the Tator halophyte, and b is the distance along the length of the district discharge, in meters, with the landing of the Eichornia halophyte, with a - 10, 20 or 30 m, a b - 50, 100 or 150 m.

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